293
Periodontal
Findings
in Adult Twins
Dorothée Aeppli,f John G. Virag*, David G. Klump*, James Bryan S. Michalowicz*, E. Hinrichs, * Nancy L. Segal, Thomas J. Bouchard, Jr., and Bruce L. Pihlstrom*
Gingivitis and Periodontitis are among the most common diseases known to man. bacterial plaque is generally accepted as the primary etiologic agent, little information is available concerning the influence that host genetic factors have on these diseases. The purpose of the present study was to examine the relative contribution of environmental and host genetic factors to clinical measures of periodontal disease through the study of both reared-together twins and monozygous twins reared apart. Probing depth, clinical attachment loss, gingivitis, and plaque were assessed from the Ramfjord teeth in 110 pairs of adult twins (mean age 40.3 years), including 63 monozygous and 33 dizygous twin pairs reared together and 14 monozygous twin pairs reared apart. Bootstrap sampling was used to estimate and provide confidence limits of between-pair and within-pair variances, intraclass correlations and heritability. Based on ratios of within-pair variances or heritability estimates, a significant (P
Periodontal
Findings
in Adult Twins
Dorothée Aeppli,f John G. Virag*, David G. Klump*, James Bryan S. Michalowicz*, E. Hinrichs, * Nancy L. Segal, Thomas J. Bouchard, Jr., and Bruce L. Pihlstrom*
Gingivitis and Periodontitis are among the most common diseases known to man. bacterial plaque is generally accepted as the primary etiologic agent, little information is available concerning the influence that host genetic factors have on these diseases. The purpose of the present study was to examine the relative contribution of environmental and host genetic factors to clinical measures of periodontal disease through the study of both reared-together twins and monozygous twins reared apart. Probing depth, clinical attachment loss, gingivitis, and plaque were assessed from the Ramfjord teeth in 110 pairs of adult twins (mean age 40.3 years), including 63 monozygous and 33 dizygous twin pairs reared together and 14 monozygous twin pairs reared apart. Bootstrap sampling was used to estimate and provide confidence limits of between-pair and within-pair variances, intraclass correlations and heritability. Based on ratios of within-pair variances or heritability estimates, a significant (P
